Step 1: Multiply the numerator and the denominator by the conjugate of the surd (i.e. sqrt(12)-sqrt(3))
=>( sqrt(12)-sqrt(3) * sqrt(12)-sqrt(3)
----------------------------------
sqrt(12) sqrt(3) * sqrt(12)-sqrt(3)
)
Tip: When you multiply the square root of a number by itself or you square the square root of a number, the result is the number (i.e. sqrt(x)*sqrt(x) = (sqrt(x))^2 = x)
Step 2: Perform the arithmetic. Since we are multiplying equations together, follow the step below
=>(
sqrt(12){sqrt(12)-sqrt(3)} - sqrt(3){sqrt(12)-sqrt(3)}
-----------------------------------------------------
sqrt(12){sqrt(12)-sqrt(3)} sqrt(3){sqrt(12)-sqrt(3)}
)